An intelligent desulfurized waste water zero-emission system and method for coal-fired power generation units

Abstract

The present invention discloses an intelligent coal-fired power generation unit desulfurization wastewater zero-discharge system and method, comprising a unit flue gas system, a sedimentation tank, a desulfurization wastewater transportation system, a DCS system, a data processing system, and an intelligent control system. The desulfurization wastewater transportation system comprises a desulfurization wastewater centrifugal pump, a total flow valve, and a branch flow valve, wherein the outlet of the total flow valve is connected to each spray gun provided on the side wall of the boiler. The DCS system is used to collect operating data of the coal-fired power generation unit in real time, and the data processing system is used to analyze and process the operating data collected by the DCS system, extracting effective operating data in real time. The intelligent control system calculates the total injection volume of the desulfurization wastewater and the injection volume, injection angle, and injection speed of each spray gun in real time based on the effective operating data, and controls the desulfurization wastewater centrifugal pump, the total flow valve, the branch flow valve, and each spray gun in real time accordingly. The present invention saves on chemicals used in desulfurization wastewater treatment, requires little investment, and requires minimal modification, while achieving harmless treatment of the injected desulfurization wastewater.

Description

Technical Field

[0001] The present invention relates to the field of industrial wastewater treatment, and in particular to a treatment process for desulfurization wastewater of thermal power units based on numerical simulation technology, and more specifically to an intelligent coal-fired power generation unit desulfurization wastewater zero-discharge system and method. Background Art

[0002] Limestone-gypsum wet desulfurization technology is the most commonly used desulfurization technology in coal-fired power plants both domestically and internationally, inevitably generating desulfurization wastewater. For this desulfurization wastewater, most domestic coal-fired power plants primarily prioritize the triple-tank process. However, the triple-tank process has the disadvantages of requiring more equipment, requiring significant investment, high operating costs, and requiring extensive equipment maintenance. These shortcomings have resulted in many power plants, despite installing these desulfurization wastewater treatment devices, experiencing high operating costs, high failure rates, and low commissioning rates. Some coal-fired power plants utilize flue gas evaporation, evaporating large amounts of desulfurization wastewater within the flue. This process also presents a range of potential risks, including ash accumulation in the flue and corrosion of the dust collector electrode plates caused by flue gas temperatures below the acid dew point. Summary of the Invention

[0003] In order to solve the problems existing in the above-mentioned desulfurization wastewater treatment process, the present invention proposes an intelligent coal-fired power generation unit desulfurization wastewater zero emission system and method, which is mainly used for the treatment of desulfurization wastewater and other sewage, saving the chemical agents used in conventional desulfurization wastewater treatment methods. Compared with conventional flue gas waste heat treatment of desulfurization wastewater, it has the characteristics of low investment and small amount of modification. At the same time, it can achieve harmless treatment of the injected desulfurization wastewater, providing an effective way for sewage treatment.

[0004] The purpose of the present invention can be achieved through the following technical solutions.

[0005] The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system of the present invention includes a unit flue gas system, a sedimentation tank, a desulfurization wastewater transportation system, a DCS system, a data processing system, and an intelligent control system;

[0006] The unit flue gas system includes a boiler, a dust collector, an induced draft fan, a desulfurization tower, and a chimney in the coal-fired power generation unit, which are connected in sequence through a flue. The lower discharge port of the desulfurization tower is connected to a sedimentation tank through a conveying pipeline;

[0007] The desulfurization wastewater transportation system includes a desulfurization wastewater centrifugal pump, a total flow valve, and a branch flow valve. The centrifugal pump inlet is connected to the liquid outlet of the sedimentation tank through a delivery pipe, the centrifugal pump outlet is connected to the total flow valve inlet through a delivery pipe, and the total flow valve outlet is connected to each spray gun arranged on the side wall of the boiler through a branch pipe. Each branch pipe is provided with a branch flow valve.

[0008] The DCS system is used to collect operating data of the coal-fired power generation unit in real time, and the data processing system is used to analyze and process the operating data collected by the DCS system, extract effective operating data in real time and transmit it to the intelligent control system. The intelligent control system calculates the total injection volume of the desulfurization wastewater and the injection volume, injection angle, and injection speed of each spray gun in real time based on the effective operating data transmitted by the data processing system, and controls the desulfurization wastewater centrifugal pump, total flow valve, branch flow valve, and each spray gun in real time based on these calculated data.

[0009] Furthermore, the sedimentation tank is used to filter the substances that are hardly soluble in water in the desulfurization wastewater generated by the desulfurization tower.

[0010] Furthermore, the spray guns are located between the burnout air and the flame deflection angle of the front wall of the boiler, and are arranged in 2 to 3 layers, with 2 to 4 spray guns on each layer, and the number of spray guns on each layer is the same or different.

[0011] Furthermore, the spray angle of the nozzle of the spray gun can be automatically adjusted. According to the temperature field distribution state in the boiler furnace, the spray angle can be adjusted to the position of the higher temperature zone to achieve balanced temperature distribution. The adjustable range is 45°~135° with the vertical water-cooled wall of the front wall.

[0012] Furthermore, the nozzle of the spray gun is an atomizing nozzle, which adopts a multi-hole arrangement. The nozzle area can be automatically adjusted. The number of nozzle holes is adjusted according to the temperature distribution in the boiler furnace to achieve regulation of the nozzle injection speed.

[0013] Furthermore, the DCS system collects operating data of the coal-fired power generation unit in real time, including the boiler's operating load, operating coal quality, total coal quantity, primary and secondary air volume, primary and secondary air temperature, economizer outlet oxygen content, furnace flue gas temperature, furnace flue gas negative pressure, steam temperature at the outlet of each heating surface, steam flow rate at the outlet of each heating surface, steam pressure at the outlet of each heating surface, cooling water flow rate, and damper opening.

[0014] Furthermore, the data processing system reads the real-time operation data of the boiler from the DCS system through Modbus communication, analyzes, judges and processes the operation data collected by the DCS system, eliminates erroneous data, corrects deviation data, and obtains valid operation data.

[0015] Furthermore, the intelligent control system acquires data from the data processing system in real time, calculates in real time the real-time velocity field and temperature field inside the boiler furnace under the current operating conditions, and based on the velocity field, temperature field and effective operating data acquired in real time, with the goal of uniform furnace temperature distribution and velocity distribution, calculates in real time the total injection amount of desulfurization wastewater that meets the furnace operation requirements and the injection amount, injection angle, and injection speed of each spray gun, and feeds back the calculation results in real time to the desulfurization wastewater centrifugal pump, the total flow valve, and each branch flow valve for flow control, as well as the control of the injection angle and injection speed of each spray gun, so as to realize the desulfurization wastewater from the desulfurization tower in the coal-fired power generation unit being sprayed into the boiler furnace.

[0016] Furthermore, the real-time velocity field and temperature field inside the boiler furnace in the intelligent control system are real-time calculation models of the velocity field and temperature field inside the boiler furnace based on numerical simulation technology and neural network technology. The establishment process is as follows:

[0017] ① Use 3D CFD software to create a 1:1 model based on the specific structural dimensions of the on-site boiler, and use meshing tools to mesh the established geometric model. Use the real-time data processing system's effective operating data under different operating conditions to set calculation boundary conditions, and obtain the heat flux density, temperature field, and velocity field of each heating surface of the boiler through hot and cold state calculations.

[0018] ② Using one-dimensional thermal fluid software, build a boiler steam-water system model at a 1:1 ratio based on the specific structural dimensions of the on-site steam-water system. Calculate the temperature distribution of the medium on each heating surface of the boiler based on the heat flux density of each heating surface obtained by three-dimensional CFD software.

[0019] ③ Import the temperature distribution data of each heating surface medium calculated by the one-dimensional thermal fluid software into the three-dimensional CFD software to optimize the heat flux density, temperature field and velocity field of each heating surface. Iterate the coupled calculation in this way to achieve the coupling of the flue gas side and the steam-water side. Finally, calculate and obtain the velocity field and temperature field inside the boiler furnace under typical operating conditions;

[0020] ④ Using the real-time effective operation data on site, verify and calibrate the calculation results of the velocity field and temperature field inside the boiler furnace under typical operating conditions obtained in step ③;

[0021] ⑤ Combined with the deep neural network, the calculation results and boundary conditions of the velocity field and temperature field inside the boiler furnace after the verification and calibration in step ④ are trained under full working conditions to realize the real-time calculation of the velocity field and temperature field inside the boiler furnace and obtain a real-time calculation model of the velocity field and temperature field inside the boiler furnace.

[0022] The purpose of the present invention can also be achieved through the following technical solutions.

[0023] The invention provides a method for zero-discharge of desulfurization wastewater from an intelligent coal-fired power generation unit, comprising the following steps:

[0024] S1: The DCS system collects real-time operating data of coal-fired power generation units, including boiler operating load, operating coal quality, total coal quantity, primary and secondary air volume, primary and secondary air temperature, oxygen content at economizer outlet, furnace flue gas temperature, furnace flue gas negative pressure, steam temperature at each heating surface outlet, steam flow rate at each heating surface outlet, steam pressure at each heating surface outlet, desuperheating water flow rate, and damper opening.

[0025] S2: The data processing system analyzes and processes the operating data collected by the DCS system, extracts effective operating data in real time and transmits it to the intelligent control system;

[0026] S3: The intelligent control system calculates the total injection volume of desulfurization wastewater and the injection volume, injection angle, and injection speed of each spray gun in real time based on the effective operating data transmitted by the data processing system, and controls the desulfurization wastewater centrifugal pump, total flow valve, branch flow valve, and each spray gun in real time based on these calculated data, thereby spraying the desulfurization wastewater in the sedimentation tank into the boiler.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] Compared with the traditional three-box process, the present invention saves costs, reduces the amount of equipment inspection and maintenance, and can harmlessly treat the injected desulfurization wastewater. At the same time, the optimal injection amount and optimal injection angle of each injection position calculated based on numerical simulation technology effectively adjust the flue gas temperature distribution in the furnace, reduce the temperature distribution difference of the medium in the furnace, and help reduce the amount of cooling water. It will not have an adverse effect on the operation of the coal-fired power generation unit and provides an effective way for sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the zero-discharge system for desulfurization wastewater of the intelligent coal-fired power generation unit of the present invention.

[0030] Figure 2 This is a schematic diagram of the desulfurization wastewater injection location for a 600MW wall-type hedge boiler in a power plant.

[0031] Figure numerals: 1-boiler, 2-dust collector, 3-induced draft fan, 4-desulfurization tower, 5-chimney, 6-sedimentation tank, 7-desulfurization wastewater centrifugal pump, 8-DCS system, 9-data processing system, 10-intelligent control system, 11-total flow valve. pipelines, Electrical connection, flue. DETAILED DESCRIPTION

[0032] The technical solutions of the present invention are described clearly and completely below with reference to the accompanying drawings and embodiments. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0033] like Figure 1 As shown, the intelligent coal-fired power generation unit desulfurization wastewater zero emission system of the present invention mainly includes the unit flue gas system, sedimentation tank 6, desulfurization wastewater transportation system, DCS system 8, data processing system 9, intelligent control system 10, etc.

[0034] The unit's flue gas system includes a boiler 1, a dust collector 2, an induced draft fan 3, a desulfurization tower 4, and a chimney 5, all connected in sequence via a flue. The lower outlet of the desulfurization tower 4 is connected to a sedimentation tank 6 via a delivery pipeline. The sedimentation tank 6 not only filters insoluble substances from the desulfurization wastewater produced by the desulfurization tower 4 through natural sedimentation, but also incorporates an ultrafiltration membrane to further enhance the filtration effect. It also temporarily stores a certain amount of desulfurization wastewater for subsequent treatment.

[0035] The desulfurization wastewater transportation system is used to transport the desulfurization wastewater pre-filtered in the sedimentation tank 6 to various required locations, and mainly includes a desulfurization wastewater centrifugal pump 7, a total flow valve 11, and a branch flow valve 12. The inlet of the centrifugal pump 7 is connected to the liquid outlet of the sedimentation tank 6 via a delivery pipeline, and the outlet of the centrifugal pump 7 is connected to the inlet of the total flow valve 11 via a delivery pipeline. The outlet of the total flow valve 11 is connected to each spray gun installed on the side wall of the boiler 1 via a branch pipeline, and each branch pipeline is provided with a branch flow valve 12.

[0036] In the above system, preferably, the spray gun is located between the burnout wind and the flame bending angle of the front wall of the boiler 1. The spray gun injection position between the burnout wind and the flame bending angle is selected based on the actual operating status of the on-site boiler, combined with the temperature field and velocity field of the numerical simulation calculation under different loads to select the best injection position. This example combines the temperature field and velocity field results of different loads calculated by on-site numerical calculation to determine that the injection position is located between the burnout wind and the flame bending angle of the front wall. In addition to ensuring a sufficiently high cross-sectional heat load to facilitate the evaporation and solidification of low-temperature wastewater in a very short time, this area is also arranged before the flame bending angle to facilitate the full mixing of wastewater solidification particles and ash particles, thereby improving the uniformity of salt content in ash and slag. The desulfurization wastewater transportation system transports the desulfurization wastewater that has been initially filtered in the sedimentation tank 6 to the injection position between the burnout wind and the flame bending angle at the front of the boiler furnace through the desulfurization wastewater centrifugal pump 7 and the transportation pipeline, and can be injected into the furnace at a certain pressure, and can control the total flow of desulfurization wastewater and the flow of each injection position in real time through the total flow valve 11 and each branch flow valve 12. In addition, the arrangement of several spray guns in this area can also ensure a higher furnace temperature during the low-load period of the coal-fired power generation unit. The spray evaporation of low-temperature wastewater is not affected by the boiler output, and the system can be put into use under full-load conditions. The spray guns are arranged in 2 to 3 layers, with 2 to 4 spray guns on each layer. The number of spray guns on each layer can be the same or different. Their position and number are determined according to the actual operating status of the on-site boiler, combined with the temperature field and velocity field calculated by numerical simulation under different loads, such as Figure 2 The layout example shown is as follows: if there are 3 spray guns on the upper layer and 2 spray guns on the lower layer, Figure 2 Part A is the spray gun mounting hole, part B is the burnout air inlet, and part C is the flame folding angle.

[0037] In the above system, preferably, the spray angle of the nozzle of the spray gun can be automatically adjusted. According to the temperature field distribution state in the boiler furnace, the spray angle can be adjusted to the position of the higher temperature zone to achieve balanced temperature distribution. The adjustable range is 45°~135° with the vertical water-cooled wall of the front wall.

[0038] In the above system, preferably, the nozzle of the spray gun is an atomizing nozzle, which adopts a multi-hole arrangement. The nozzle area can be automatically adjusted. The number of nozzle holes is adjusted according to the temperature distribution in the boiler furnace to realize the regulation of the nozzle injection speed. Precise positioning injection can also be achieved for farther locations to ensure sufficient mixing of desulfurization wastewater and flue gas and good evaporation effect.

[0039] The DCS system 8 is used to collect real-time operating data of the coal-fired power generation unit, mainly including the operating load of the boiler 1, the operating coal quality, the total coal quantity, the primary and secondary air volume, the primary and secondary air temperature, the oxygen content at the economizer outlet, the furnace flue gas temperature, the furnace flue gas negative pressure, the steam temperature at the outlet of each heating surface, the steam flow rate at the outlet of each heating surface, the steam pressure at the outlet of each heating surface, the attemperating water flow rate, the damper opening, etc. The data processing system 9 is used to analyze and process the operating data collected by the DCS system 8, extract effective operating data in real time and transmit it to the intelligent control system 10. Based on the effective operating data transmitted by the data processing system 9, the intelligent control system 10 calculates in real time the total injection volume of the desulfurization wastewater and the injection volume, injection angle, and injection speed of each spray gun, and controls the desulfurization wastewater centrifugal pump 7, the total flow valve 11, the branch flow valve 12, and each spray gun in real time based on these calculated data.

[0040] In the above system, preferably, the data processing system 9 reads the real-time operation data of the boiler from the DCS system 8 via Modbus communication, analyzes, judges and processes the operation data collected by the DCS system 8, eliminates erroneous data, corrects deviation data, and obtains valid operation data. Specifically,

[0041] ① The data processing system 9 receives real-time operating data from the DCS system 8. This data contains key information such as timestamps, operating load, and operating coal quality. The received real-time operating data is initially verified to check for correct formatting, timestamp continuity, and obvious logical errors (such as negative temperature values or pressure values outside the equipment design range).

[0042] ② During the initial verification process in step 1, any data that can be directly identified as abnormal using pre-set rules (e.g., extreme values exceeding the physical device's capabilities) is considered erroneous data. This data is then eliminated and replaced using the "previous second data replacement method," replacing the current erroneous data with normal operating data transmitted from the previous second. This strategy assumes that data changes should remain within a reasonable range over a short period of time, so the previous second's operating data can serve as a reasonable approximation of the current data.

[0043] ③For the data that cannot be directly judged correct by the preset rules during the preliminary verification process of step ①, compare it with the data under the same operating load conditions in the historical database. Calculate the deviation between the current data and the historical data, including but not limited to statistical indicators such as mean deviation and standard deviation deviation, to evaluate whether the current data significantly deviates from the normal range of historical data. Set a threshold. When the deviation of the current data exceeds this threshold, it is considered to be seriously deviated from the historical data, which may be caused by sensor failure, data transmission errors, etc. For cases that are judged to be seriously deviated from historical data, the "previous second data replacement method" is also used to eliminate and replace them to ensure the continuity and rationality of the data flow, and ultimately obtain valid operating data.

[0044] In the above system, preferably, the intelligent control system 10 acquires data from the data processing system 9 in real time, calculates in real time to form the real-time velocity field and temperature field inside the boiler furnace under the current operating conditions, and based on the velocity field, temperature field and effective operation data acquired in real time, with the goal of uniform furnace temperature distribution and velocity distribution, calculates in real time the total injection amount of desulfurization wastewater that meets the furnace operation requirements and the injection amount, injection angle, and injection speed of each spray gun, and feeds back the calculation results in real time to the desulfurization wastewater centrifugal pump 7, the total flow valve 11, and each branch flow valve 12 for flow control, as well as the control of the injection angle and injection speed of each spray gun, so as to realize the desulfurization wastewater from the desulfurization tower 4 in the coal-fired power generation unit being sprayed into the boiler furnace.

[0045] The real-time velocity field and temperature field inside the boiler furnace in the intelligent control system 10 are real-time calculation models of the velocity field and temperature field inside the boiler furnace based on numerical simulation technology and neural network technology. The specific establishment process is as follows:

[0046] ① Utilizing 3D CFD software, a 1:1 model was constructed based on the specific structural dimensions of the on-site boiler 1. The resulting geometric model was meshed using professional meshing tools (such as ANSYS ICEM). Calculation boundary conditions were set using real-time operational data from the data processing system 9 under different operating conditions. Heat flux density, temperature field, and velocity field were calculated for each heating surface of boiler 1 through hot and cold state calculations.

[0047] ②At the same time, a boiler steam-water system model is built based on the specific structural dimensions of the on-site steam-water system using one-dimensional thermal fluid software. The temperature distribution of the medium on each heating surface is calculated based on the heat flux density of each heating surface obtained by three-dimensional CFD software.

[0048] ③ The temperature distribution data of the medium on each heating surface calculated by the one-dimensional thermal fluid software is imported into the three-dimensional CFD software to optimize the heat flux density, temperature field and velocity field of each heating surface. In this way, the coupling calculation is iteratively performed to achieve the coupling of the flue gas side and the steam-water side. Finally, a more accurate velocity field and temperature field inside the boiler furnace under typical operating conditions are calculated, which improves the accuracy of the calculation inside the boiler furnace;

[0049] ④ Using real-time and effective on-site operating data, verify and calibrate the calculation results of the velocity field and temperature field inside the boiler furnace under typical operating conditions obtained in step ③ (specifically, verify and calibrate the real-time calculated values of the velocity field and temperature field inside the boiler furnace) to improve the accuracy of the calculation model;

[0050] ⑤ Combined with the deep neural network, the calculation results and boundary conditions of the velocity field and temperature field inside the boiler furnace after the verification and calibration in step ④ are trained under full working conditions to realize the real-time calculation of the velocity field and temperature field inside the boiler furnace and obtain a real-time calculation model of the velocity field and temperature field inside the boiler furnace.

[0051] Based on the principle of the above-mentioned intelligent coal-fired power generation unit desulfurization wastewater zero discharge system, the present invention also proposes an intelligent coal-fired power generation unit desulfurization wastewater zero discharge method, which specifically includes the following steps:

[0052] S1: The DCS system 8 collects the operating data of the coal-fired power generation unit in real time, including the operating load of boiler 1, operating coal quality, total coal quantity, primary and secondary air volume, primary and secondary air temperature, oxygen content at the economizer outlet, furnace flue gas temperature, furnace flue gas negative pressure, steam temperature at each heating surface outlet, steam flow rate at each heating surface outlet, steam pressure at each heating surface outlet, desuperheating water flow rate, and damper opening;

[0053] S2: The data processing system 9 analyzes and processes the operating data collected by the DCS system 8, extracts effective operating data in real time and transmits it to the intelligent control system 10;

[0054] S3: The intelligent control system 10 calculates the total injection volume of the desulfurization wastewater and the injection volume, injection angle, and injection speed of each spray gun in real time based on the effective operation data transmitted by the data processing system 9, and controls the desulfurization wastewater centrifugal pump 7, the total flow valve 11, the branch flow valve 12, and each spray gun in real time based on these calculated data, so as to spray the desulfurization wastewater in the sedimentation tank 6 into the boiler 1 to meet the furnace operation requirements of the boiler 1.

[0055] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. An intelligent coal-fired power generation unit desulfurization wastewater zero emission system, comprising a unit flue gas system, wherein the unit flue gas system comprises a boiler (1), a dust collector (2), an induced draft fan (3), a desulfurization tower (4), and a chimney (5) in the coal-fired power generation unit connected in sequence through a flue, characterized in that: The flue gas system of the unit is also equipped with a sedimentation tank (6), a desulfurization wastewater transportation system, a DCS system (8), a data processing system (9), and an intelligent control system (10); the lower discharge port of the desulfurization tower (4) is connected to the sedimentation tank (6) through a transportation pipeline; The desulfurization wastewater transportation system comprises a desulfurization wastewater centrifugal pump (7), a total flow valve (11), and a branch flow valve (12); the inlet of the centrifugal pump (7) is connected to the liquid outlet of the sedimentation tank (6) through a delivery pipeline; the outlet of the centrifugal pump (7) is connected to the inlet of the total flow valve (11) through a delivery pipeline; the outlet of the total flow valve (11) is connected to each spray gun provided on the side wall of the boiler (1) through a branch pipeline; each branch pipeline is provided with a branch flow valve (12); the spray gun is located between the burnout air and the flame deflection angle of the front wall of the boiler (1); The DCS system (8) is used to collect the operation data of the coal-fired power generation unit in real time. The data processing system (9) reads the real-time operation data of the boiler from the DCS system (8) through the Modbus communication method, analyzes, judges and processes the operation data collected by the DCS system (8), eliminates erroneous data, corrects the deviation data, obtains effective operation data, and transmits it to the intelligent control system (10). The intelligent control system (10) obtains the data of the data processing system (9) in real time, calculates in real time the real-time velocity field and temperature field inside the boiler furnace under the current working condition, and calculates in real time the total injection amount of desulfurized wastewater that meets the furnace operation requirements and the injection amount, injection angle, and injection speed of each spray gun based on the velocity field, temperature field and the effective operation data obtained in real time, with the goal of uniform furnace temperature distribution and velocity distribution, and feeds back the calculation results in real time to the desulfurized wastewater centrifugal pump (7), the total flow valve (11), and each branch flow valve (12) for flow control, and each spray gun for injection angle and injection speed control, so as to realize the desulfurized wastewater of the desulfurization tower (4) in the coal-fired power generation unit to be sprayed into the boiler furnace; The real-time velocity field and temperature field inside the boiler furnace in the intelligent control system (10) are real-time calculation models of the velocity field and temperature field inside the boiler furnace based on numerical simulation technology and neural network technology. The establishment process is as follows: ① Use 3D CFD software to create a 1:1 model based on the specific structural dimensions of the on-site boiler, and use meshing tools to mesh the established geometric model. Use the real-time data processing system's effective operating data under different operating conditions to set calculation boundary conditions, and obtain the heat flux density, temperature field, and velocity field of each heating surface of the boiler through hot and cold state calculations. ② Using one-dimensional thermal fluid software, build a boiler steam-water system model at a 1:1 ratio based on the specific structural dimensions of the on-site steam-water system. Calculate the temperature distribution of the medium on each heating surface of the boiler based on the heat flux density of each heating surface obtained by three-dimensional CFD software. ③ Import the temperature distribution data of each heating surface medium calculated by the one-dimensional thermal fluid software into the three-dimensional CFD software to optimize the heat flux density, temperature field and velocity field of each heating surface. Iterate the coupled calculation in this way to achieve the coupling of the flue gas side and the steam-water side. Finally, calculate and obtain the velocity field and temperature field inside the boiler furnace under typical operating conditions; ④ Using the real-time effective operation data on site, verify and calibrate the calculation results of the velocity field and temperature field inside the boiler furnace under typical operating conditions obtained in step ③; ⑤ Combined with the deep neural network, the calculation results and boundary conditions of the velocity field and temperature field inside the boiler furnace after the verification and calibration in step ④ are trained under full working conditions to realize the real-time calculation of the velocity field and temperature field inside the boiler furnace and obtain a real-time calculation model of the velocity field and temperature field inside the boiler furnace.

2. The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system according to claim 1 is characterized in that: The sedimentation tank (6) is used to filter the substances that are difficult to dissolve in water in the desulfurization wastewater generated by the desulfurization tower (4).

3. The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system according to claim 1 is characterized in that: The spray guns are located between the burnout air and the flame folding angle of the front wall of the boiler (1), and are arranged in 2 to 3 layers, with 2 to 4 spray guns on each layer, and the number of spray guns on each layer is the same or different.

4. The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system according to claim 3 is characterized in that: The spray angle of the nozzle of the spray gun can be automatically adjusted. According to the temperature field distribution state in the boiler furnace, the spray angle can be adjusted to the position of the higher temperature zone to achieve balanced temperature distribution. The adjustable range is 45°~135° with the vertical water-cooled wall of the front wall.

5. The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system according to claim 3 is characterized in that: The nozzle of the spray gun is an atomizing nozzle, which adopts a multi-hole arrangement. The nozzle area can be automatically adjusted. The number of nozzle holes is adjusted according to the temperature distribution in the boiler furnace to achieve the regulation of the nozzle injection speed.

6. The intelligent coal-fired power generation unit desulfurization wastewater zero discharge system according to claim 1 is characterized in that: The DCS system (8) collects the operating data of the coal-fired power generation unit in real time, including the operating load of the boiler, the operating coal quality, the total coal quantity, the primary and secondary air volume, the primary and secondary air temperature, the oxygen content at the economizer outlet, the furnace flue gas temperature, the furnace flue gas negative pressure, the steam temperature at the outlet of each heating surface, the steam flow rate at the outlet of each heating surface, the steam pressure at the outlet of each heating surface, the desuperheating water flow rate, and the damper opening.

7. A method for zero discharge of desulfurization wastewater based on the intelligent coal-fired power generation unit zero discharge system for desulfurization wastewater according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: The DCS system (8) collects the operating data of the coal-fired power generation unit in real time, including the operating load of the boiler (1), the operating coal quality, the total coal quantity, the primary and secondary air volume, the primary and secondary air temperature, the oxygen content at the economizer outlet, the furnace flue gas temperature, the furnace flue gas negative pressure, the steam temperature at the outlet of each heating surface, the steam flow rate at the outlet of each heating surface, the steam pressure at the outlet of each heating surface, the attemperating water flow rate, and the damper opening; S2: The data processing system (9) analyzes and processes the operating data collected by the DCS system (8), extracts effective operating data in real time and transmits it to the intelligent control system (10); S3: The intelligent control system (10) calculates the total injection volume of the desulfurized wastewater and the injection volume, injection angle, and injection speed of each spray gun in real time based on the effective operation data transmitted by the data processing system (9), and controls the desulfurized wastewater centrifugal pump (7), the total flow valve (11), the branch flow valve (12), and each spray gun in real time based on these calculated data, thereby spraying the desulfurized wastewater in the sedimentation tank (6) into the boiler (1).

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